Safety device for catching or collecting objects in well bores



Dec. 1952 J. M. CLARK 2,620,035

SAFETY DEVICE FOR CATCHING OR COLLECTING OBJECTS IN WELL BORES Filed Dec. 19, 1950 2 SHEETS-SHEET 1 IN VENT OR JflA IES M 6242K ATTORNEY Dec. 2, 1952 2,620,035

J. M. CLARK SAFETY DEVICE FOR CATCHING OR COLLECTING OBJECTS IN WELL BORES Filed Dec. 19, 1950 2 SHEETS-SHEET 2 l6 l L INVENTOR JAMES M. CLARK ATTORNEY Patented Dec. 2, 1952 UNITED STATES PATENT. OFFICE SAFETY DEVICE FOR CATCHING R COL- LECTING OBJECTS IN WELL BORES 4 Claims.

This invention relates to a safety device for catching or collecting falling objects in well bores and more particularly to a new and useful safety device for use with tubing string including drill pipe in well bores in connection with the running of packers, fishing tools or any other tool having an outside diameter of sufiicient size to become wedged in a well bore by objects dropping within the well bore from one position to another, or objects dropped into the Well bore from the surface. The invention further relates to such a device that can be inverted and utilized for catching or collecting objects in well bores and pushing the same downwardly as the device is pushed or moved downwardly in the well bore. Such objects as are referred to above are usually referred to as "junk and may comprise tong keys, bolts, sections of slip sections, or hammer heads; parts of bridge plugs, cement plugs, float collars, packers, etc. that have been drilled up within the well bore; or other objects which might drop or be dropped within or into the well bore and cause the hole to be plugged by such objectsbecoming wedged between the packer or tool and the casing or well bore.

The primary object of the invention is to provide a device of the aforementioned character constructed of a flexible, resilient material whereby the external and internal diameters or dimensions of the device may be made as large as possible with relation to the diameter of th well bore or well casing, to allow the device to accommodate more and larger objects or fragments of junk and to hold to a minimum the size or amount of objects or junk fragments which can pass between the device and the well bore or well casing, such flexible resilient construction also permitting the device to pass through restrictions or irregularities in the well bore without damage or permanent change in shape since, due to its resilient construction, after passing such restrictions or irregularities, the device will readily resume its normal shape and dimensions.

A further object of the invention is to provide a safety device of the aforementioned character provided with fluid passageways of such construction that fluid passages are assured even though the device swells to full well bore size whereby to efiectively prevent swabbing action when pulling the string out of the well bore and floating action when passing the string into the well bore.

A still further object of the invention is to provide a safety device of the aforementioned character which, if ever lost in the well bore will not cause other tools and the like to become stuck;

which is easily drilled up or circulated out of the well bore, or both; and which makes it practical to wash over a stuck tubing string on which such a flexible safety device has been run.

A still further object of the invention is to provide a safety device of the aforementioned character which may be'secured to the tubing string by means of frictional engagement only with such tubing string.

Another object of the invention is to provide an adapter plug for use in combination with the safety device when it is desired to utilize the safety device in inverted position and attached to the lower end of a tubing string or tool.

Other and further objects of the invention will become apparent as the description proceeds, reference being made to the accompanying drawing forming a part of the present disclosure, wherein:

Fig. 1 is a to plan view of a safety device constructed in accordance with the teaching of my invention;

Fig. 2 is a side elevational view of Fig. 1, parts being shown in section;

Fig. 3 is a top plan view of the adapter plug;

Fig. 4 is a side elevational view of Fig. 3, parts being shown in section;

Fig. 5 is a side elevational view with parts in section; and

Fig. 6 is a side elevational view with parts in section.

Referrin in detail to the drawing, wherein for purposes of illustration the preferred embodiments of my inventionare illustrated, it will be seen in Figs. 1 and 2 that the safety device A comprises an annular member generally indicated by reference numeral I. Themember l is preferably composed of a flexible, resilient material such as rubber, either natural or synthetic, plastics, fabrics, or a combination of these materials, or other flexible, resilient materials.

It will be noted that the inner diameter of one end portion 2 of the annular member I is smaller than the inner diameter of the other end portion 3 thereof, and such end portions are connected by means of a shoulder 4, preferably frusto-conical, extending between such two end portions. The inner diameter of the end portion 2 is preferably just slightly less than the drill or other tubing string Hi to which the device is to be secured, whereby the resilient end portion 2 may be stretched to be positioned on the tubing string and will thereafter be secured in position by means of the frictional engagement between the inner surface of the end portion 2 and the tubing string I6. The device A may be mounted on the tubing string IS in the upright position illustrated in Fig. 5, usually at a point immediately above the tool that it is to protect, whereby it will function to collect falling objects in the well bore, or it may be placed on the tubing string 22 in an inverted position at any desired location, for instance as shown in Fig. 6, whereby it will function as a junk pusher to catch or collect objects and force them downwardly in the well bore as the device is so moved by the tubing string.

A plurality of circumferentially spaced, longitudinally extending grooves 5 is provided in the outer surface of the annular member I. Inclined apertures 6 are provided in, or open into said grooves 5 and extend through the annular member I.

The outer surface I of most of the end portion 2 of the member I is preferably tapered inwardly toward the free end 8 thereof and the grooves 5 preferably extend entirely throughout the length of the member I from the tapered surface I to the upper end 9 of the member I. By placing the grooves 5 on the outside of themember I, fluid passageways through the device A are assured even though the member I swells to full Well bore size. The apertures 6 also aid in assuring such fluid passageways since under certain circumstances the upper ends of the member I might be pressed outwardly to partially close the upper open ends of the passageways 5, in which event, circulation through the device may continue through the lower ends of the passageways 5 and apertures 6. Th safety device A being resilient is adapted to grip the tubing I6 or it can be forced downwardly so as to grip the upset portion ll of the tubing I6. Furthermore, the collar I8 may act as a seat to eifectively prevent any further downward movement of the safety device A. The coupling I8 connects the tubing I6 to a tool or additional tubing 19.

It is believed that the mode of operation of my safety device will be obvious from the foregoing description in its use surrounding a tubing string, either for catching falling objects in the well bore or for catchin and pushing objects downwardly of the well bore in inverted position. It is pointed out, however, that by the flexible and preferably resilient structure utilized, as compared with a similar rigid structure, the outer diameter of the annular member I may be made as large as possible in relation to the diameter of the well bore and the internal diameter of the end portion 3 may be correspondingly increased in size, whereby my safety, device may accommodate more and larger fragments of junk and will also hold to a minimum the size and amount of junk fragments which pass between the annular member I and the wall of the well bore. or casing. The disadvantages of a large outer diameter for the member I are, of. course, a tendency to swab and to stick in tight places. In addition, the safety device might stick if junk became wedged between it and thewall of the hole. By my novel construction, however, these disadvantages are overcome due to the flexibility and resiliency of the device, and the groove means, or groove and aperture means which assure fluid passages even though the cup swells to full well bore size due to fluid pressure.

, It is obvious, of course, that the resiliency of my safety device allows it to pass through irregularities or restrictions in the well bore without permanent change in its configuration whereas large diameter devices made of rigid material would stick, be bent out of shape, or broken when passing through such places.

In the event the flexible device of my invention is lost in the hole, it is usually possible to push or pull the tool with which it is run to protect, by or through the device itself, since it does not readily become stuck in the well bore. Furthermore, my safety device is easily drilled up or circulated out of the well bore, or both. It is also practical to wash over the stuck tubing string on which the flexible device of my invention has been run, whereas this, of course, would be impracticable if a relatively large diameter device were made of steel or similar rigid material.

It is sometimes desirable to operate the safety device A as a junk pusher, as referred to above, with the devic in inverted position and secured on the lower end of a tubing string or tool as shown in Fig. 6. To so provide for the operation of my safety device A, I have provided an adapter plug B illustrated in Figs. 3, 4 and 6 of the drawing. The adapter plug B may be constructed of the same materials mentioned above in connection with the safety device A or it may be made of any material which is readily millable or drillable.

The adapter plug B comprises a tubular memher is having a passageway ll extending therethrough and provided adjacent its upper end with an outwardly directed annular flange I2 havinga lower frusto-conical surface I3 adapted to seat upon the frusto-conical shoulder 4 within the annular member I. The outer diameter of the central portion I3 is substantially equal to or slightly less than the inner diameter of the end portion 2 of the member I and the outer diameter of the flange I2 is substantially equal to or slightly less than the inner diameter of the end portion 3 of the member I. The lower end I4 of the plug B is provided with any suitable means such as a screw thread I5 to connect the same to the screw threads 23 of the lower end of a tubing string 22 or the lower end of a tool.

It will be obvious that when the plug B is inserted in the safety device A with the frustoconical portion I3 of the flange I2 thereof resting upon the shoulder 4, that the lower threaded end I4 of the plug will project outwardly beyond the end 8 of the member I and such plug B may therefore be utilized to rigidly secure the safety device A to the end of a tubing strin or tool. With this connection of the safety device, as indicated above, it is usually, but not necessarily, utilized in inverted position as a junk pusher.

It will be obvious that my new safety device and adapter plug therefor may be made in any desired size and while I have illustrated and described in detail herein the preferred embodiments of my invention, it is to be understood that the invention is not limited to the specific embodiments illustrated, since modifications thereof may occur to those skilled in the art, and it is my desire to cover all such modifications as come within the scope of the appended claims.

I claim:

1. A safety device for catching objects in well bores comprising a resilient annular member having two distinct end portions, the inner diameter of one end portion of said annular member being smaller than the inner diameter of the other end portion thereof, a shoulder between said two end portions, a plurality of circumferentially spaced longitudinally extending grooves in the outer surface of said annular member providing fluid passageways, apertures in said grooves extending through said annular member, the outer surface of said one end portion of the annular member being tapered inwardly toward the free end thereof, a tubular resilient adapter plug having an outwardly projectin annular flange at one of its ends and a screw thread at the other end thereof, said plug being positioned in said annular member with said annular flange in seating engagement with said shoulder and the other end of said plug projectin outwardly beyond the end of said annular member.

2. A safety device for catching objects in well bores comprising a resilient annular member having two distinct end portions, the inner diameter of one end portion of said annular member being smaller than the inner diameter of the other end portion thereof, a shoulder between said two end portions, a plurality of circumferentially spaced longitudinally extending grooves in the outer surface of said annular member providing fluid passageways, apertures in said grooves extending through said annular member, a tubular resilient adapter plu having an outwardly projecting annular flange at one of its ends and a screw thread at the other end thereof, said plug being positioned in said annular member with said annular flange in seating engagement with said shoulder and the other end of said plug projecting outwardly beyond the end of said annular member.

3. A safety device for catching objects in well bores comprising a resilient annular member having two distinct end portions, the inner diameter of one end portion of said annular member being smaller than the inner diameter of the other end portion thereof, a shoulder between said two end portions, a plurality of circumferentially spaced longitudinally extending grooves in the outer surface of said annular member providing fluid passageways, apertures in said grooves extending through said annular member, a tubular adapter plug having an outwardly projecting annular flange at one of its ends positioned in said annular member with said annular flange in engagement with said shoulder, the other end of said plug projecting outwardly beyond the end of said annular member and having means thereon to connect the same to a tubing string.

4. A safety device for catching objects in well bores comprising a, resilient annular member having two distinct end portions, the inner diameter of one end portion of said annula member being smaller than the inner diameter of the other end portion thereof, a shoulder between said two end portions, a plurality of circumferentially spacer longitudinally extending grooves in the outer surface of said annular member extending through the upper surface thereof providing fluid passageways, and apertures in said grooves extending through said annular member.

JAMES M. CLARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,487,061 Heflin Mar. 19, 1924 1,623,543 Jones et al. Apr. 5, 1927 1,730,804 Christenson, J-r. Oct. 8, 1929 1,849,096 Kibele Mar. 15, 1932 1,880,004 Worswick Sept. 27, 1932 2,233,692 Bryant Mar. 4, 1941 2,265,615 Stalter Dec. 9, 1941 2,506,069 Dalton May 2, 1950 2,565,455 Miller Aug. 21, 1951 

